11 21 500 Replacing crankshaft (N20, N26)

Special tools required:

Necessary preliminary tasks:

Remove ENGINE .
Mount engine on ASSEMBLY STAND .
Remove VIBRATION ABSORBER .
Remove oil sump . See 11 13 000 REMOVING AND INSTALLING, SEALING OR REPLACING OIL SUMP (N20, N26) or 11 13 000 REMOVING AND FITTING, SEALING OR REPLACING THE OIL SUMP (N20 ALL-WHEEL DRIVE VEHICLE) .
Remove OIL PUMP .
Remove timing CHAIN MODULE .
Remove CHAIN MODULE for oil pump.
Remove CYLINDER HEAD .
Remove FLYWHEEL .
Remove all PISTONS .

Release all screws (1).

Fig 1: Identifying Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Undo screws (10 through 1) from the outside to the inside.

Fig 2: Crankcase Lower Section Bolts Tightening/Loosening Sequence (N20)

Courtesy of BMW OF NORTH AMERICA, INC.

Remove the crankcase lower section (1) in the direction of the arrow towards the top.

Fig 3: Removing Crankcase Lower Section

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Remove crankshaft with aid of a second person.
Weight of crankshaft approx. 21 kg.

Remove crankshaft (1) upward in direction of arrow.

Remove and replace (if applicable) BEARING SHELLS and guide bearing shells.

Fig 4: Removing Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: If the screw (1) is undone, the oil spray nozzle (2) must be readjusted.

Fig 5: Identifying Oil Spray Nozzle Screw

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Setting the oil nozzle to the crankcase.

Place feeler gauge (2) between oil nozzle (1) and crankcase.

Fig 6: Placing Feeler Gauge Between Oil Nozzle And Crankcase

Courtesy of BMW OF NORTH AMERICA, INC.

Adjust feeler gauge to 0.40 mm.

Bring oil nozzle into contact with the feeler gauge by pressing lightly.

Tighten bolt (1).

Tightening torque. 11 11 3AZ .

Fig 7: Adjusting Feeler Gauge

Courtesy of BMW OF NORTH AMERICA, INC.

Clean all sealing surfaces (1) with special tool 11 4 470 .

Insert all CRANKSHAFT MAIN BEARINGS .

Installation note:

Remove residue of seals from the crankcase (2).

Check fitting bushes (1) for damage and replace if applicable.

Oil all bearing points adequately with engine oil.

Fig 8: Locating Crankcase Seals Residue

Courtesy of BMW OF NORTH AMERICA, INC.

IMPORTANT: Insert crankshaft with aid of a second person.
Weight of crankshaft approx. 21 kg.

Insert crankshaft (1).

Fig 9: Inserting Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Installation note:

Check durability of sealing compound, do not use sealing compound that has expired.

Maximum processing time of the SEALING COMPOUND 2.2 10 minutes.

Apply sealing compound in the stated areas with a width of 2.0 to 2.6 mm.

Fig 10: Identifying Sealing Compound Applying Areas

Courtesy of BMW OF NORTH AMERICA, INC.

Fit crankcase lower section (watch fitting bushes).

Fig 11: Installing Crankcase Lower Section

Courtesy of BMW OF NORTH AMERICA, INC.

Fig 12: Crankcase Lower Section Bolts Tightening/Loosening Sequence (N20)

Courtesy of BMW OF NORTH AMERICA, INC.

Please observe the tightening sequence of the screws (1 to 10).

Join screws (1).

Fig 13: Tightening Crankshaft Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Mark all screws (1) with a crosswise colored mark.

Fig 14: Identifying Screws Mark

Courtesy of BMW OF NORTH AMERICA, INC.

Retighten all screws using special tools 00 9 120 .

Tightening torque 11 11 1AZ .

Installation note:

After tightening all screws, the colored mark must be aligned in the same way.

Fig 15: Tightening Screws Using Special Tools (00 9 120)

Courtesy of BMW OF NORTH AMERICA, INC.

All screws (1) from the inside to the outside.

Tightening torque 11 11 2AZ .

Fig 16: Tightening Crankcase Screws

Courtesy of BMW OF NORTH AMERICA, INC.

Fit special tool 11 6 252 with magnetic foot on special tool 11 4 440.

Clamp special tool 11 6 251 on special tool 11 6 252 .

Position special tool 11 6 251 with button on the flat side of the crankshaft.

Press crankshaft (1) in direction of arrow up to stop.

Set dial gauge with knurled screw (2) on zero.

Fig 17: Pressing Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Press crankshaft (1) in direction of arrow from right to left up to stop.

Determine CRANKSHAFT AXIAL CLEARANCE .

Fig 18: Pressing Crankshaft

Courtesy of BMW OF NORTH AMERICA, INC.

Turn crankshaft (1) via the central bolt with special tool 00 2 010 to determine the COEFFICIENT OF FRICTION .

Fig 19: Turning Crankshaft (N55 Shown)

Courtesy of BMW OF NORTH AMERICA, INC.

Replace front CRANKSHAFT SEAL .

Replace CRANKSHAFT SEAL (transmission side).

Assemble engine.